This specification relates generally to climate control systems and, more particularly, to a climate control system capable of exhausting air ducts associated therewith prior to initiating heating, cooling, ventilating or other climate control operations
The advantages of evacuating air or otherwise ventilating the interior portions of buildings and other structures have been widely appreciated for a number of years. For example, during the summer months, the air in the attic or other above-ground uninsulated portion of a building can easily reach temperatures exceeding 130 degrees Fahrenheit. As the heated air penetrates the insulation separating the uninsulated portion of the building from an insulated portion of the building typically used as the living and/or working space thereof, the temperature in the insulated portion of the building begins to climb. The reverse occurs during winter when the colder air in the uninsulated portion of the building causes the temperature in the insulated portion of the building to drop as the colder air penetrates the insulation separating the uninsulated portion of the building from the insulated portion thereof.
For a number of years, buildings and other structures have been equipped with climate control systems designed to maintain the temperature within a portion of the building, typically, the aforementioned insulated portion used as the living and/or working space thereof, within a pre-selected temperature range, thereby preventing that portion of the building from reaching undesired temperature extremes. In various configurations thereof, such a climate control system may include a heating system which serves to warm the interior of the building during cold weather, a ventilating system for circulating air through the interior of the building, a cooling system which serves to cool the building during hot weather, and/or another type of climate control system. Typically, however, climate control systems are configured to include a heating unit such as a furnace, a cooling unit such as an air conditioner and a central unit which includes an air handler where air withdrawn from the interior of the building is treated by the selective heating or cooling thereof. As climate control systems also include one or more fans to draw air from the interior of the building into the air handler of the central unit for treatment and/or one or more blowers to force the treated air back into the interior of the building, by operating these fans and/or blowers without the use of the furnace or air conditioner to treat the air, a typical climate control system is also capable of performing certain ventilating operations.
Regardless of their particular configuration, an important component of all heating, ventilating and cooling systems, as well as any other interior climate control system which integrates one or more of the aforementioned heating, ventilation and/or cooling systems into an integrated climate control system, is the air distribution systemxe2x80x94a network of one or more air ducts used to circulate air throughout the building. Typically, the air distribution system is comprised of inlet and outlet sides. The inlet side includes one or more air intake registers and a first duct system which extends from the air intake registers to an inlet side of a junction box, which, in turn, is coupled to the inlet side of the central unit. Air drawn into the air intake register is transferred via the first duct system and the inlet junction box to the central unit for treatment, typically, using a thermal transfer process by which the air is either heated or cooled. The treated air exits the outlet side of the central unit where it enters an outlet junction box coupled to the outlet side of the air distribution system. From the outlet junction box, the treated air is forced through a second duct system and out one or more air outlet registers.
In most buildings, the ducts which respectively form part of the inlet and outlet sides of the air distribution system are located in the attic, walls, crawl spaces and other uninsulated portions of the building. As a result, air residing within these ducts, for example, cooled or heated air which is left in the ducts after the air conditioner or furnace cycles off for an elongated period after successfully adjusting the temperature within the building to a desired temperature, may either cool or heat rapidly and then penetrate the interior living space of the building. Of even greater concern, when the air conditioner or furnace cycles back on, the cooled or heated air left in air ducts, particularly those forming part of the outlet side of the air distribution system, would be quickly pumped into the interior living space of the building. If the first air pumped into the interior living space has remained in the air ducts on the outlet side of the air distribution system for a period of time, the temperature differential between that air and the desired temperature for the interior living space could very possibly be greater than the temperature differential between the current and desired temperatures for the interior living space. Under such circumstances, since the climate control system would initiate a cycle, for example, a cooling cycle, by pumping in air hotter than the current temperature of the interior living space, the initial stage of the cooling cycle would tend to increase the total time needed to cool the interior space of the building to the desired temperature.
U.S. Pat. No. 4,765,231 to Aniello discloses an air conditioning system in which, when a potentially harmful level of smoke is detected, supply fan motors associated with the duct work are reversed in direction so as to evacuate the smoke through registers in the rooms and into the duct work. The smoke is then exhausted away from the building through an outside ventilating unit. However, while Aniello does remove air from ducts located on the outlet side of an air conditioning system, Aniello is clearly directed to an smoke exhaustion system intended for operation under emergency conditions and nowhere contemplates incorporating the disclosed exhaustion techniques into a climate control system.
In recent years, a number of new products and/or techniques which enhance the insulative characteristics of buildings have been developed. While it is widely recognized that recently constructed buildings are better insulated against temperature changes resulting from temperature differentials between the insulated interior space of the building and the outside/uninsulated interior space of the building, such improvement products and/or techniques have also caused certain adverse effects. Specifically, while modern construction is better insulated to prevent heat transfers, the lack of fresh air being introduced into such buildings has caused a variety of physical ailments in those living and/or working at such buildings and/or structures. Thus, newly constructed buildings have a greater need for suitable ventilating systems than buildings constructed in years past. While a variety of ventilating systems have been disclosed, generally such ventilating systems are designed to draw air out of the interior space of a building directly and are not fully integrated with the climate control system of the building.
Finally, in my prior U.S. patent application Ser. No. 09/399,389, I disclosed an air duct evacuation system capable of exhausting air from ducts located on the outlet side of an air handler. However, the disclosed air duct evacuation system lacked any provision for replenishing the air forcibly exhausted from the building. The absence of such an air replenishment system raises the concern that a pressure differential between the interior space of the building and the outside may develop over time, particularly in those modem buildings tightly sealed to prevent ventilation between the interior space of the building and the outside which naturally occurred in older structures. For example, if the interior space of a building was at a lower pressure relative to the outside, the potential exists for radon or other naturally occurring, but quite harmful, gases to more readily collect within the building. While it is acknowledged that the adverse effects of such a pressure differential have not been fully explored, it would clearly be preferable to prevent such pressure differentials from ever developing.
Therefore, what is needed is a climate control system uniquely configured to withdraw unsuitable air from ducts located on an outlet side thereof. It is, therefore, an object of the invention to provide such a climate control system.
In one embodiment, the present invention is directed to a climate control system for treating air within an interior space of a building. The climate control system includes a central unit, a first air duct system coupled to an inlet side of the central unit, a second air duct system coupled to an outlet side of the central unit and an air evacuation system. The climate control system is configured such that, prior to the central unit thereof treating air withdrawn from the interior space of the building through the first air duct system and returning the treated air to the interior space of the building through the second air duct system, the air evacuation system operates to withdraw air from the second air duct system.
In one aspect of this embodiment of the invention, the climate control system further includes a controller coupled to the air evacuation system and the central unit. The controller first actuates the evacuation of air from the second air duct system and, subsequent to the evacuation of the second air duct system, the controller then actuates the treatment of the air withdrawn from the interior space of the building through the first air duct system. In another, the controller initiates actuation of the air evacuation system and the central unit by executing an actuation sequence. In a further aspect thereof, the actuation sequence includes first and second steps. In the first step, the controller actuates the air evacuation system for a pre-selected period of time, and, in the second step, the controller actuates the central unit until a measurable physical condition meets a pre-selected threshold value. In a still further aspect thereof, the pre-selected period of time is selected based upon the time required for the air evacuation system to evacuate air from the second air duct system and the selected period of time is allowed to expire and the air evacuation system deactuated prior to the controller actuating the central unit. In accordance with a further aspect thereof, the measurable physical condition is temperature and the controller includes a sensor for determining temperature of the interior space of the building.
In still further aspects thereof, the central unit is alternately configured to treat air within the interior space of the building by warming the air withdrawn from the interior space of the building through the first air duct system and then returning the warmed air to the interior space of the building through the second air duct system or to treat air within the interior space of the building by cooling the air withdrawn from the interior space of the building through the first air duct system and then returning the cooled air to the interior space of the building through the second air duct system. If the central unit heats the withdrawn air, the controller executes the actuation sequence upon determining that the temperature of the interior space of the building has dropped below a preselected threshold value. Conversely, if the central unit cools the withdrawn air, the controller executes the actuation sequence upon determining that the temperature of the interior space of the building has risen above a pre-selected threshold value.
In another embodiment thereof, the present invention is directed to a climate control system for treating air within an interior space of a building. The climate control system includes a central unit, a first air duct system coupled to an inlet side of the central unit, a second air duct system coupled to an outlet side of the central unit and an air evacuation system. The central unit treats air withdrawn from the interior space of the building through the first air duct system and returns the treated air to the interior space of the building through the second air duct system while the air evacuation system operates to withdraw air from the second air duct system prior to the central unit treating air withdrawn from the interior space of the building through the first air duct system and returning the treated air to the interior space of the building through the second air duct system. The air evacuation system includes a ventilation duct having a first end in communication with the second air duct system and a second end having an opening located outside the building and a exhaust fan for drawing air out of the second air duct system and into the ventilation duct. In accordance with this embodiment of the invention, the exhaust fan is operable to draw air out of the second air duct only when the central unit is not returning treated air to the interior space of the building through the second air duct system.
In one aspect thereof, the air evacuation system further includes a damper attached to the first end of the ventilation duct and pivotable between a closed position in which the damper prevents air from flowing into the ventilation duct and an open position in which the second air duct system is in communication with the ventilation duct. In another, the controller is coupled to the exhaust fan and the damper for actuating the evacuation of the second air duct system and to the central unit for actuating the treatment of the air withdrawn from the interior space of the building through the first air duct system and, in still another, the controller initiates actuation of the air evacuation system and the central unit by executing an actuation sequence comprised of a first step in which the controller issues a first control signal to the damper to cause the damper to move from the closed position to the open position and a first control signal to the exhaust fan to cause the exhaust fan to begin rotating such that air is drawn out of the second air duct system and into the ventilation duct and a second step, executed a pre-selected period of time after the first step is executed, in which the controller issues a second control signal to the damper to cause the damper to move from the open position to the closed position, a second control signal to the exhaust fan to cause the exhaust fan to stop rotating, and a first control signal to the central unit to cause the central unit to begin treating air withdrawn from the interior space of the building through the first air duct system. As before, the pre-selected period of time may be selected based upon the time required for the air evacuation system to evacuate the second air duct system. In this aspect, however, the actuation sequence may further include a third step in which the controller issues a second control signal to the central unit which causes the central unit to stop treating air withdrawn from the interior space of the building through the first air duct system when a measurable physical condition, for example, temperature, meets a pre-selected threshold value.
In still another embodiment thereof, the present invention is directed to a climate control system for treating air within an interior space of a building which includes a central unit, a first air duct system having an outlet side coupled to an inlet side of the central unit, a second air duct system having an inlet side coupled to an outlet side of the central unit, and an air evacuation and exhaustion system. The central unit treats air withdrawn from the interior space of the building through the first air duct system and returns the treated air to the interior space of the building through the second air duct system. The air evacuation and exhaustion system, on the other hand, withdraws air from the second air duct system and exhausts the withdrawn air from the building. In accordance with this embodiment of the invention, the air evacuation and exhaustion system withdraws and exhausts air from the second air duct system as a preparatory step performed in advance of the central unit treating air withdrawn from the interior space of the building and returning the treated air to the interior space of the building through the second air duct system.
In one aspect thereof, the climate control system further includes an air replenishment system for replenishing air evacuated from the second air duct system. In another, the climate control system further includes an air outlet junction box coupled between the outlet side of the central unit and the inlet side of the second air duct system. In this aspect of the invention, treated air pumped out of the central unit is returned to the interior space of the building through the air outlet junction box and the second air duct system.
In still another aspect of this embodiment of the invention, the air evacuation and exhaustion system includes a ventilation duct having a first end in communication with the air outlet junction box and a second end having an opening located outside the building, and a exhaust fan for drawing air out of the second air duct system and into the ventilation duct. In this aspect, the exhaust fan is operable to draw air out of the second air duct only when the central unit is not returning treated air to the interior space of the building through the air outlet junction box and the second air duct system.
In a still further aspect of this embodiment of the invention, the exhaust fan is supportably mounted within the air outlet junction box. In another, the air evacuation and ventilation system includes a damper pivotable between a closed position in which the damper prevents air from flowing into the ventilation duct and an open position in which air may flow through the damper and into the ventilation duct. In this aspect, the damper is also supportably mounted within the air outlet junction box.
In other aspects thereof, the air evacuation and ventilation system may include a booster fan for assisting the exhaust fan in forcing air, drawn out of the second air duct, out the opening located outside the building. In various ones of these aspects, the booster fan may be supportably mounted at the second end of the ventilation duct, within the ventilation duct, at a location intermediate the first and second ends thereof, or within the second air duct system.
In still other aspects of this embodiment of the invention, the air replenishment system may include an air replenishment duct having a first end having an opening located outside the building and a second end in communication with the central unit of the climate control system. In further aspects thereof, a flapper valve movable between a first position in which the flapper valve prevents outside air from being drawn into the air outlet junction box through the air replenishment duct and a second position in which the flapper valve allows outside air to be drawn into the air outlet junction box through the air replenishment duct may be supportably mounted within the air replenishment duct at a location intermediate the first and second ends thereof.
In still further aspects thereof, the climate control system may include a controller coupled to the exhaust fan and the damper for actuating the evacuation of the second air duct system, to the central unit for actuating the treatment of the air withdrawn from the interior space of the building through the first air duct system and to the flapper valve for actuating replenishment of the air evacuated from the second air duct system.
In certain further aspects thereof, the controller initiates actuation of the air evacuation and ventilation system, the central unit and the air replenishment system by executing an actuation sequence. In one such further aspect, the actuation sequence is comprised of a first step in which the controller issues a first control signal to the damper to cause the damper to move from the closed position to the open position and a first control signal to the exhaust fan to cause the exhaust fan to begin rotating such that air is drawn out of the second air duct system and into the ventilation duct and a second step, executed a pre-selected time period after the first step, in which the controller issues a second control signal to the damper to cause the damper to move from the open position to the closed position, a second control signal to the exhaust fan to cause the exhaust fan to stop rotating, a first control signal to the central unit to cause the central unit to begin treating air withdrawn from the interior space of the building through the first air duct system and a first control signal to the flapper valve to cause the flapper valve to move from the closed position to the open position. By executing this actuation sequence, the central unit generates a flow of treated air through the air outlet junction box which draws outside air, through the air replenishment duct, thereinto.
In another aspect, the pre-selected period of time is selected based upon the time required for the air evacuation system to remove all untreated air from the second air duct system and, in still other aspects, the actuation sequence may include third and/or fourth, steps. In the third step, the controller issues a second control signal to the flapper valve which causes the flapper valve to move from the open position to the closed position and, in the fourth step, the controller issues a second control signal to the central unit which causes the central unit to stop treating air withdrawn from the interior space of the building through the first air duct system. In the aspect of the invention in which the actuation sequence includes the fourth step, the fourth step would be executed when a measurable physical condition meets a preselected threshold value.